A need exists in many industrial processes for an effective and efficient method for removing carbon dioxide from a secondary fuel source, such as a top gas fuel source, in a direct reduction process. In other words, a need exists in many industrial processes for an effective and efficient method for removing carbon dioxide from an otherwise waste fuel source, allowing it to be used as a primary fuel source without emissions problems. In some cases, government policy has required such carbon dioxide removal, and the need for carbon dioxide emissions control will only increase in the future. Direct reduction involves the reduction of iron oxide ores into metalized iron pellets, lumps, or compacts, where the iron oxide is reduced by a gas containing hydrogen and/or carbon monoxide, resulting in a carbon dioxide byproduct.